Huawei HCIE-Datacom V1.0 H12-891_V1.0 Exam Dumps: Updated Questions & Answers (October 2025)

The free mobility solution in Huawei iMaster NCE-Campus allows:

Centralized policy management via the controller

Security group-based policies, decoupled from IPs/VLANs

Automatic policy delivery, no need to configure repeatedly per device

Dynamic mapping of users and IPs via security group subscriptions

Exact Extract - Huawei iMaster NCE-Campus Solution White Paper:

“Free mobility uses security groups and centralized control to enable consistent policy enforcement, avoiding repetitive configurations and simplifying policy management.”

Comprehensive and Detailed In-Depth Explanation:

Prefix Segment:

Represents adestination prefixin the network.

APrefix SID (Segment Identifier)is a globally unique SID that maps to anIP prefixand is within theSRGB (Segment Routing Global Block)range.

Therefore,Cis correct.

Ais incorrect because a prefix SIDis within the SRGB range, not out of it.

Adjacency Segment:

Represents alink (adjacency)between two nodes.

AnAdjacency SIDislocally significantand typically allocated from theSRLB (Segment Routing Local Block)range.

It uniquely identifies a link between nodes in thesource node’s local routing table.

Therefore,Dis correct, whileBis incorrect because an adjacency SID is not necessarily an offset within the SRGB.

Comprehensive and Detailed Explanation:

✔All four egress modesare supported inHuawei CloudCampus Virtualized Fabricto provideflexibility in connecting external networks.

✔Modes Explained:

✅Layer 3 Shared Egress→ Multiple VNs share asingle Layer 3 gatewayfor external communication.

✅Layer 2 Shared Egress→ Multiple VNs share the sameLayer 2 linkto the external network.

✅Layer 3 Exclusive Egress→ Each VN has its ownseparate Layer 3 gatewayto external networks.

✅Layer 2 Exclusive Egress→ Each VN has its owndedicated Layer 2 linkfor external connectivity.

????Reference:Huawei HCIE Datacom – CloudCampus Fabric Egress Modes

Understanding SRLB (Segment Routing Local Block)

????What is SRLB?

SRLB (Segment Routing Local Block)is arange of local MPLS labelsused bySegment Routing (SR-MPLS).

These labels areonly relevant to the local routerand arenot advertised to other routers.

????Key SR-MPLS Label Blocks:

✅SRGB (Segment Routing Global Block)– Globally significant labels shared among routers.

✅SRLB (Segment Routing Local Block)– Locally significant labels, not shared.

Why is the Answer TRUE?

✅SRLB labels are only locally defined and are NOT distributed via IGP (OSPF or IS-IS).

✅They are used for local forwarding decisions within an SR-enabled router.

✅Only SRGB labels are advertised to ensure consistent global label assignment.

Real-World Application:

Traffic Engineering (TE):Uses SRLB forcustom local path optimizations.

Segment Routing Networks:Ensuresscalable MPLS forwardingwithout requiring full LDP signaling.

✅Reference:Huawei HCIE-Datacom Guide – Segment Routing Label Blocks (SRGB & SRLB)

Huawei’sOPS (Open Programmability System)enables programmable interactions with devices through Python-based templates. In Huawei's OPS Python environment:

The classOPSConnectionis used to manage device interactions.

It includes methods like:

get()

post(self, uri, req_data)→ used tocreate resources

put(),delete(), etc.

This aligns with RESTful API semantics, and the post() method in the context given is used correctly.

Correct answer: A. TRUE

Network Slicing Using Channelized Sub-Interfaces and FlexE

Bothchannelized sub-interfacesandFlexE (Flexible Ethernet)are used fornetwork slicing, but they have differentapplication scenarios:

✅A. Channelized sub-interface is recommended for interfaces with bandwidth < 50 Gbit/s.

Channelized sub-interfacessplit a physical interfaceinto multiple logical sub-interfaces.

Best for lower-bandwidth links (<50 Gbit/s).

✅B. FlexE is recommended for 50GE and higher-rate interfaces.

FlexEdivides a high-bandwidth physical link(e.g.,100GE, 400GE) into multiple virtual slices.

Used in high-speed backbone and data center networks.

✅C. Only FlexE-based network slicing can be deployed across OTN devices.

FlexE is compatible with Optical Transport Network (OTN)and can be used for long-haul slicing across OTN.

❌D. Only channelized sub-interface-based network slicing can be deployed across MSTP devices.

Incorrect!While MSTP supports channelized interfaces,FlexE is not restricted to MSTP deployment.

Reference from Huawei HCIE-Datacom Documentation:

Huawei FlexE Technology Whitepaper – Network Slicing in Transport Networks

HCIE-Datacom Training Material – Channelized Sub-Interface and FlexE in Network Slicing

Route Target (RT)is aBGP extended community attributeused inMPLS Layer 3 VPNs (L3VPNs)to control theimport and exportof VPN routes between differentVPN instances (VRFs).

Explanation of Correct Answers:

✅A. Each VPN instance is associated with one or more pairs of VPN Target attributes, used to control VPN routing information advertisement and reception between sites.

Each VRF (VPN Routing and Forwarding instance) has an associated RTthat determines which routes areimported and exportedbetween VPNs.

RTs enableinter-VPN communicationwhile maintaining separation between VPN customers.

✅B. Export Target and Import Target are independent of each other and support multiple values to implement flexible VPN routing information advertisement and reception control.

TheExport RTspecifies which routes should be advertised.

TheImport RTspecifies which routes should be accepted into a VRF.

These can beconfigured independentlyto control traffic flow between VPNs.

✅C. RTs are classified into two types: Export Target and Import Target.

Export Target: Defineswhich VPN routes are advertised.

Import Target: Defineswhich VPN routes are accepted.

A VPN instance can have multiple RTsto allow flexibility.

✅D. The RT value is advertised to neighbors through the BGP extended community attribute in Update messages.

RTs are carried in BGP UPDATE messagesas part of theBGP extended community attribute, enabling VPN route exchange between PEs.

Reference from Huawei HCIE-Datacom Documentation:

Huawei MPLS VPN Configuration Guide – Route Target (RT) Concepts

HCIE-Datacom Study Material – BGP Route Advertisement in MPLS VPNs

This statement confuses congestion management with congestion avoidance:

Congestion Management: Refers to techniques like PQ, CQ, WRR, etc., to schedule packets in queues — i.e., manage how packets are sent, not discarded.

Congestion Avoidance: Techniques like WRED are used to preemptively discard packets to avoid full queues — these do discard packets.

Hence, congestion management does NOT discard packets — it's about controlling transmission order and prioritization.

Correct answer: B. FALSE

Comprehensive and Detailed In-Depth Explanation:

To supportSR-MPLS (Segment Routing over MPLS),OSPFusesType 10 Opaque LSAsto advertiseSegment Routing (SR) capabilities and information.

Type 10 Opaque LSA (B): Used fordistributing application-specific informationwithin an OSPF area. In SR-MPLS, it carries theSID/Label mappingsand other SR-related information.

Type 7 NSSA External LSA (A):Used to advertise external routes within an NSSA, not related to SR-MPLS.

Type 1 Router LSA (C):Advertises the router’s interfaces and links but does not carry SR-specific information.

Type 2 Network LSA (D):Advertises the links of abroadcast or NBMA network, not used for SR-MPLS.

Therefore, the correct answer isB (Type 10 Opaque LSA), as it enables theadvertisement of SR information.

MPLS Positioning in the TCP/IP Model

MPLS (Multiprotocol Label Switching) operatesbetween the Data Link Layer (Layer 2) and the Network Layer (Layer 3).

✅MPLS is protocol-independentand supports variousnetwork layer protocols (IPv4, IPv6, VPN, etc.)by using labels instead of traditional IP routing.

✅How MPLS Works:

MPLSassigns labels to packets, allowing fast forwarding based on the label rather than a routing table lookup.

SupportsLayer 3 VPNs (L3VPNs), Layer 2 VPNs (L2VPNs), and MPLS Traffic Engineering (MPLS-TE).

✅Why MPLS is Between Layer 2 and Layer 3?

MPLS adds a label between the Layer 2 (Ethernet, PPP) and Layer 3 (IP) headers, effectivelycreating a separate forwarding mechanism.

Label Switching Routers (LSRs) forward packets based on labels instead of IP addresses, reducing processing time.

Reference from Huawei HCIE-Datacom Documentation:

Huawei MPLS Technology Guide – MPLS Architecture and Label Switching

HCIE-Datacom Study Material – MPLS Positioning and Functionality in TCP/IP